Abrading



C. H. KASCH ABRADiNG June 4, 1940.

Filed Dec. 29. 1938 7 Sheets-Sheet 1 INVENTOR Hi I will! It? I! J ATTORNEY June 4, 1940. c. H. KA'SCH' ABRADING Filed Dec. 29. 1938 7 Sheets-Skeet? INVENTOR AT I'ORNEY c. H. KAscl-l June 4, 1940.

ABRADING 7 Sheets-Sheet 5 Filed Dec. 29. 1938 61 fl KAJGH INVENTOR ATTORNEY June 4, 1940. c. H. KASCH 2,203,530

ABRADING Filed Dec. 29, 1938 7 Sheets-Sheet 4 6'. AAJGH INVENTOR ATTORNEY June 4, 1940. c, H KASCH 2,203,530

ABRADING Filed Dec. 29, 1938 7 Shet-Sheet 6 C. H. KASCH June 4, 1940.

ABRADING Filed Dec. 29, 1938 INVENTOR AT TORNEY 7 Sheets-Sheet 7 Patented June 4 1940/ UNITED STATES PATENT O-FFlCE ABRADING Charles H. Kasch, Davenport, Iowa, assignor to H. Simmons, Davenport, Iowa Application December 29, 1938, Serial No. 248,167.

22 Claims.

In grinding scalloped-edge blades, it been customary to bend the blade about a cylindrical forming member and grind off a facette in the curved position. This practice is not particuo larly satisfactory since the bend in positions close to the end of a blade will not be the same as at positions removed from the end. When the curved bevel is producedin this manner, slight differences in the curvature of the blade will produce substantial variations in; the size of the scallops. This prior method, furthermore, limits both the hardness of the steel which is employed and the size of the scallops. Thus, very hard steels which would make excellent to a large radius of curvature, as employed for large scallops, would break such a steel blade. With the milder steels, such as are of necessity commonly employed, only the larger scallops may :19 be produced, since bending tothe small radius of curvature, as would be necessary, would result in breaking or permanently bending such a blade. Steel sufficiently mild that small scallops can be formed therein by this prior method 3 would produce only inferior blades.

In accordance with. the present invention, bevels, as above described, are produced by grinding with a grinding wheel which is rotated on an axis therethrough and revolved about an 40 axis perpendicular to the surface of the workpiece about the center of curvature of the circular bevel or scallop to be produced. Following this grinding, the work and the grinding tool are relatively moved to present a fresh working surface, and the grinding step repeated.

In the case of grinding scalloped-edge blades, the grinding of any one scallop is completed while the wheel is revolved only part of the way about the center of curvature. Duringa part to of the remaining time, i. e., while the wheel com-1 blades can not beemployed since bending even.

the following cycle; first, movement into engage ment with the work-piece, second, grinding a circular bevel, third, movement out of engage ment with the Work-piece, and fourth, movement to the first position. During the fourth stage of 5 the cycle, the axis of revolution is moved with respect to the work-piece to the next desired position. By this method of blade-grinding, blades of exceptionally hard steel may be produoed, inasmuch. asthe blades are not bent durl0 ing manufacture.

The machine shown in the I accompanying drawings illustrates a machine in accord with the present invention and for performing the 7 above described process. It should be understood that my inventioncomprises not only the specific machine hereinafter described and shown inthe drawings but also the combinations of parts defined in the subjoined claims.

In thedrawings: V

Fig. 1 is a plan of a machine in accordance with this invention and which is particularly adapted to the manufacture of relatively short bread-slicing blades; I

Fig. 2 is a front elevation of the machine shown in. Fig. 1;

Fig. 3 is a section substantially on the line 3-3 in Fig. 1; I

Fig. 4 isa left end elevation of the machine with portions of the left frame plate bro-ken away 3g better to show the carriage structure;

Fig. 5 is a right end elevation; 1 Fig. 6 is a partialvertical section through th grinder head; I I I Fig. 7 is'a bottom plan of the grinder head; Fig. 8 is a section on line 88 in Fig. 4; Fig. 9 is a plan of the work-holder with the pivot supports thereof shown in section; and

Figs. 10, 11, andlZ are sections on. the lines It-Il], I'I--I I, and I2--I2, respectively, in Fig. 9. 4

The machine shown in the accompanying drawings has a base I provided at each end with a vertical frame member 2, 3 between which extend a pluralityof frame rods 4, 5, 6. A carriage I, which includes the grinding head 8, is

mounted to slide on the rods 5 and 6. The machine also comprises a blade-holder assembly fl,

the details ofwhich are shown in Figs. 9 to 12.

Referring now more. particularly to Figs. 1, 3, a

and 4; the carriage 1 comprises a main carriage frame member It to which a motor-carrying plate II is pivoted at I2. The plate II is provided with a slot M which cooperates with a bolt I5 in an arm l6 of the member ID for adjustmentof the motor plate I I about pivot I2 pulley |8 drives through a belt 20. The pulley l9 and also a pulley 22 are keyed to a tubular shaft 2|, the pulley 22 being arranged to drive a pulley 23 through a belt 24.

rotatable on sleeve 26 on adjusting arm 21. The

adjusting arm has a ring 28 which slides readily about flange 29 on the carriage frame l6. A bolt 30 passes through the sleeve 26 and is movable in a an arcuate slot in the carriage, the center of curvature of the slot being the sameas of the flange 29. The gear 25 meshes with a gear 3| head plate 41 being carried by the bearing 46.

which is carried by a bearing 32 within the flange 29 and concentric therewith whereby, when belt 24 is tightened by moving the adjusting arm 21. the gears 25 and 3| remain in mesh. The above described train from the pulley l8 through the gear 3|, during the normal operation of the machine, is constantly driven by the motor H.

A clutch shaft 33 has a keyway most of its length and is mounted for rotation in frame plates 2 and 3. Abracket 34 is mounted on carriage frame l0 and is provided with a pair of arms 35 through each of which the clutch shaft 33 passes. A clutch arm 36 is positioned between the arms 35 and is keyed to shaft 33 for sliding movement therealong as a portion of the carriage and for rotation therewith when the shaft is rotated by control means hereinafter described and shown in detail in Fig. 5. The end of the clutch arm 36 remote from shaft 33 is positioned below and 'in the axial line of the gear 3|.

A'tubular shaft 31 extends through the gear 3| and is freely rotatable therein. At the lower end of the shaft 31 and integral therewith is a pinion 38 between which and the carriage frame a thrust bearing is positioned. An external clutch plate 39 is slidably keyedto the upper end of shaft 31 and in lowered position engages an internal clutch face in the gear 3|. The clutch plate 39 isrigidly secured to clutch rod 49, which; is slidable in theshaft 31; by a cap 4| which screw-threadedly engages both plate 39 and rod 40- A spring 42 is positioned about rod 40 between the pinion 38 and a pair of adjusting-nuts 43 on the rod. The lower end of rod-40 has a plate 44 for engagement with clutch arm 36. f

This construction allows. the tubular shaft 31 to be spring-pressed upwardly inall positions of the clutch, and the clutch to be held normally in engagement by adjustable spring pressure.

The grinding head assembly 8 is supported by a pairof bearings 45, 46 carried by the-carriage frame ID, the tubular shaft 2| heretofore mentioned being carried by the bearing 45, and the A third bearing 48 about the lower end of shaft 2| cooperates with plate 41 to hold the shaft and plate relatively concentric- The shaft 2|, together with its drive plate 49 which is secured to the lower end thereof, and the head plate 41 may each be rotated independently of the other. A ring gear 5|] is securedto and completely encompasses the head plate 41 in a position to engage at all times the pinion 38. Normally, except when work is beingpositioned in or removed from the work-holder assembly 9,-the clutch-is in engagement, :wherefore the head plate is normally The pulley 23 is keyed to a sleeve integral with the gear 25 which is freely 48, an opening is formed in the tubular part of carriage frame |0 between the bearings and '46' in which the plug 5| fits screw-threadedly.

An oil deflector 52 is placed on the tubular shaft. To confine the oil, grease retainers 53 are positioned between pulley 22 and the carriage frame Ill, between the head plate 41 and the carriage frame I6, and between the head plate 41 and the drive plate 49.

Referring now most particularly to Figs. 6 and 7, a guide plate 54 is secured as by bolts to the lower surface of the head plate 41, and is provided with a pair of guide channels 55, 56. A slide 51 is arranged to move in the guide channels, and to be clamped in adjusted position by a clamp bar 58 in channel 56 (see Fig. 3). The cooperating faces of the guide channels and of the slide are inclined inwardly and downwardly, whereby tightening of the clamp bar under ac,- tion of set screws 59 will hold the slide firmly to the lower surface of the guide plate. An arm 66 on the slide has a bolt 6| affixed therein parallel to the direction of the guides 55, 56. This bolt 6| is arranged to pass through a pair of lugs 62 on the guide plate with a thumb nut 63 on the bolt between the lugs. With clamp bar 58 in open position, fine adjustment of slide 51 may be attained by turning the thumb nut, which adjustment may then be retained by setting the clamp bar.

A shaft 64 is supported for rotation by a pair of bearings 65, 66 carried by the slide 51, the exposed portion of the shaftbetween the bearings being knurled. This shaft 64 is so positioned that in all adjustments of the slide 51 the axis of the shaft 64 intersects the axis of tubular'shaft 2|, and so that adjustment of the slide moves the shaft 64 toward and from said shaft 2|. The shaft 64 is angularly related to the plate 54 so that the inner end of the shaft upon which the abrasive wheel 61 is secured is lower than the outerend. I

- Immediately above the shaft 64, a stub shaft 68 is supported by the slide, the shaft 68 screwthreadedly engaging the slide and being provided with a nut to lock the shaft in adjusted position. The outer end of the stub'shaft is provided with a bearing 69 upon the outer portion of which is clamped a drive wheel 16 which may be rubber covered. The shaft 68 and drive wheel 16 are so related to the shaft 64 and drive plate 49 that the wheel is driven by the plate and in turn drives the shaft 64. Thus the wheel 10 may be positioned substantially midway between and in contact with both the plate and the shaft. Relative to the axis of rotation of, the grinding head. When the shaft 64 passes above the work-holding :clamp *9, the wheel 6! will, if the slide is properly adjusted, grind a single {scallop in the edge of the work. Adjustment of slide 51 by the thumb 311111363 will vary the size of the scallop cutin the work. During the remainder of rotation ofthe grindinghead, no grindingis eflected and the wheel Bl is spaced from the work. During this latter period, the carriage assembly is indexed, by means presently described, to a position for grinding the next scallop.

The lower two-thirds of the periphery of th head plate 4'! is primarily a plain cylinder, but is provided with a gear segment 12 extending partially around the lower third and with a similar gear segment 73 partially around the middle third, positioned diametrically of segment I2. movable shaft, to which is also secured a, gear 7,5;whereby thegears Whand 15 are constrained to :rotate and translate inunison. This pair of gears is mounted for vertical movement in the carriage frame, at a position such that a long toothc'lfi of gear H rides ,on the cylindrical portion of the head and prevents iturning of the gear 14 exceptwhen the ordinary teeth of gear I'M .are in engagement with one or the other of the gear segments 12, 13. When the gear M engages either.segmenhthegear is given one complete revolution, after which tooth 15 again rides on the cylindrical portion of the :head. Thus the gear 14 is a so-called intermittent gear, producingintermittent rotation in eitherof its positions of adjustment.

.In the lower positionof thegear '15, it engages .a gear 11 fixed on a shaft, to which the gear 18,.and the bevel ,gear .19 are also fixed, so that the gears .11, 18, and F9 rotateasaunit. .Thegear .15 may be raised toa position midway inelevationbetween gears "and .18, in which position engagement witheither gear 11 or gear 80 to en--v gage with the other, i. e.,.in the described position, the teeth of gear .15 will be in alignment with the spaces betweencthe teeth of thegear H .or .80 with which it. is not engaged; Gear .19 engages and rotates a secondbevelgear Bl which is non-.rotatably attached by a shaft to the bevel gear .82. The :bevel .gear 82 engages another bevel gear 83 which isnfixed to an internally screw-threaded sleeve 84 rotatably carriedbythe carriage frame plate it! (see Fig. 8) I he sleeve irl alisin engagement ,withthe lead screw 65 fixed in,.the frame of the machine, whereby rotation of the sleeve .84, :eifected by rotation of gear M through the described gear train,.effects movement of the carriage along .the machine. As the gear 1.4 is driven intermittently by the gearlsectors 12 and 1,3,it will. be seen this structure periodically indexes the carriage. This indexing occurs between grinding periods of the machine cycle.

Now, therefore, assuming the machine to be in theposition shown in ,Eigs. 2 3, and Fly-1311B clutch being in engagement, ,the grinding head will .rotate clockwise in plan. .After rotating through A gear 14 is mounted on a vertically a small arc, the grinding wheel will engagethe vwork;.and upon further rotation cut'a scallop fromathe work-piece, after which further rotation of the head disengages the wheel from the work. Subsequently thereto and prior to reengagement of the wheel with the work, the gear sector 12 engages the gear 14 and indexes the carriage to the right to position for grinding the next scallop.

Considering now the mechanism 'for shifting the transmission heretofore'described, the grinder head is provided with a cam 86 on its upper surface, located substantially above the slidemechanism. An arm 87, provided with a cam roller 88, is slidably keyed on shaft 89, the arm being so proportioned that when gear 15 is in lower position and the carriage indexes to the right,,the cam roller 88 will lie in the path of the cam =86. When the carriage has been indexed to the right end of the machinethe cam and cam roller will turn the shaft 8% counterclockwise,

as seen in Fig. 4. A pair of lugs a! extend upwardly fromthe carriage frame plate iii and are each. provided with an opening through which the shaft 88 extends. An apertured lever 92 is positioned between lugs 9! and is slidably keyed to the shaft 89. This construction constrains the lever 92 to move along the shaft with the carriage. A link 93 is pivoted to the upper end of lever 92 and, at its other end, the link is pivoted adjustably in a slot to an. arm of the lever 94, pivoted at $5 to the bracket 9'! of the carriage frame I 0. The other end of lever 94 is bifurcated and provided with pins 98 which extend into a groove in the shaft upon which the gears M and 15 are secured. To counterbalancethe weight of this shaft and the gears, a weight 99 is secured to lever94.

Actuation of cam roller 88 by reversing cam 86 effectuates movement of gear l5 from its lower position in which the machine indexes to the right to. its raised position in which the machine indexes to the left. I

To understand properly the timing of the indexing and reversing operations, it should be I noted that when indexing to the right the seallops are formed in the forward edge oi? the blade, and upon reversing, the. blade-holder and blade arepivoted about axis Hlii so that the blade is positioned forwardly of the grinding wheel and is ground onits then rear edge. Considering now the question of timing, starting from the position shown in. Figs. .2, 3, and 4, after the head turns a short distance, say about 30, with tooth E5 on space I), the grinding operation commences and then lasts for about 120. Durthis 120, the tooth "it passes along the blank space adjacent the sector it. about 60"., the tooth l8 rides on blank space a (seeFig. 7), during which no grinding occurs. During the third stage, the sector '22 engages'the gear 74 and indexes. During the fourth stage, the gear 14 rides on the blank space-b forabout 60, passing the initial position and repeating the cycle of operation. When the last scallop during indexing to the right has been cut and tooth H5 is riding on space a, the saints engages cam roller 88, shifting gear Mto raised position and turning the blank holder about axis liiil, by means hereinafter described. Due to shifting of the gear, instead of indexing being effected by sector gear 72, the gear rides on the blank space besidesector 12, during which the right hand scallop is ground on theback side of the work.

Followingthiatooth Hi rides onispaceb for about- Thereafter, .ior

bar IIO.

60, followed by the grinding stage ofthe cycle.

To shift the gear 14 when the carriagereaches the left extremity of its movement, a sleeve IN is revolvably mounted on shaft I02, and is provided with a pair of lever arms I03 and I04. Arm I03 extends downwardly and rearwardly and is provided at its lower end with a cam roller I05 positioned to be engaged and elevated by cam 86. An adjustable link I06 is pivoted at one end to the upper end of arm I 04 and at its other end to the upper end of lever arm I01 keyed to shaft 89. As viewed in Fig. 4, when the cam 80 elevates roller I05, the levers I03, I04, I01, and 94 are turned clockwise thereby depressing the gear 14 and placing the machinein position for right hand indexing.

The work-holder involves a clamp arranged to rotate on a bearing at each end thereof. 'Complemental pivot brackets I08 at each end are arranged to rotate in any suitable bearings I09 in frame members 2, 3 and are positioned so that the pivotal axis 'of the brackets intersects the axis of rotation of the grinder head. The main clamp element III) is adjustably secured to the brackets, as by bolts movable in slots in the brackets. A cooperating clamp member III is provided at each end with a pivot pin I I2. The two clamp members H0 and III are pivotally secured'together by fingers II3 having recesses to receive pins I I2 and which are secured to mem- The edges of clamp members H0 and I I I rearward of pivotal axis I00 are spaced apart, and springs II4 are located therebetween so that the edges of the members adjacent axis I00 are held firmly together. At the end of member II I, slots are provided in which manually actuatable cams II5 are pivoted on the pins IIB, the cams operating against wear plates H1 in clamp member III). A pair of spring guides II8 are adjustably secured by bolts in slots HQ with the unsecured ends thereof extending over the edge of the clamp. A pin I is secured to the end of each of the guides to engage in an opening in a blade blank to, assist in the proper positioning thereof in the clamp. As the clamp is considerably removed from the axial line I00, a pair of.

adjustable counterweights is secured to the brackets to counterbalance theclamp.

' A gear I2I is keyed to a-short section of shafting, which in turn is keyed in an opening in bracket I08 at the left of the machine so that turning of the gear turns the clamp. A lever I22 is keyed to shaft 89 and has an adjustable length link I23 pivoted thereto at a distance'adjustable from the shaft 89. The opposite end of the link I23 is pivoted to operating arm I24 of sector gear I25 which engages gear I2I When shifting to right hand indexing, shaft 89 is turned clockwise, as shown in Fig. 4 as heretofore explained, resulting in clockwise movement of the clamp assembly to the position shown in Fig. 3. When indexing is reversed to left hand indexing, the shaft 89, lever I22, and the clamp assembly turn counterclockwise, as viewed in Fig. 4.

Brackets I08 are provided with stop arms I26 which cooperate'with either of a pair of adjustable stops I21 to limit the movement of the are carried by an arm I of'the carriage. The support I28 is carried rearwardly of the support I29, the former supporting the clamp during right hand indexing and the latter during left hand indexing.

Each of the supports I28, I29 is pivoted to the arm I30, as at I3I, I32, and is provided with stop arms I33 for cooperation with abutments I34 on arm I30. Each support is provided withan actuating arm I35 against which a springpressed plunger I30 acts to hold its respective support in normal vertical supporting position with the stop arm I33 against the abutment I34. By pressing either actuating arm I35 against the action of its plunger I36, the support is moved away from position supporting the clamp, where-I by the clamp may be turned to the other position thereof or turned to neutral position below the axis I00.

An actuator I38 is positioned nearthe right hand end of the machine and in fixed longitudinal relationship with respect to the cam roller 88. The actuator is arranged to extend through opening I39 in the arm I30 and into contact with arm I35 to tilt support I28 out of supporting position. lT-he cam roller 88 and actuator I38 are so related that the support I28 is removed and the support snapping into normal position I when the clamp has reached proper position.

Referring now to the control mechanism, shown most particularly in Fig. 5 but also disclosed in Figs. 1 and 2, an arm MI is clamped as by a bolt I42 through openings in a split sleeve on the end of arm I4I to a collar which is keyed to transmission shaft 89, which is turned when the index shifting gears are shifted. This structure allows arm I4I to reciprocate along shaft 89 in an adjustably fixed radial position with respect thereto. The arm I is positioned on the shaft 89 between two springs I43, I44, the spring I43 forcing the arm toward the frame plate 2 and being strong enoughto overcome the force of spring I44 which is employed to prevent rattling of arm I59 in certain positions of the machine. The lower end of the arm I lies normally in the same plane as a trigger I45 pivoted at I46 and provided with a hook I41. A lever I48 is fixed to clutch shaft 33, one arm of the lever having a shoulder I49 engageable with hook I41. In engaged position of the trigger hook I41 and shoulder I49, the shaft 33 is in position such that the clutch is in engagement. An adjustable pressure spring I50 is arranged to press against lever I48 and to turn the lever and clutch shaft clockwise, as viewed in Fig. 5, so that when the trigger is disengaged from the lever the clutch ismoved to disengaged position. A rod I5I is provided with a shoulder I52 and a reduced end portion I53 which is arranged to slide in a rotatable apertured pin I54 in the lower end of lever I48. The opposite end of the rod I5I is pivoted on the pin I55 carriedby a plate I56 which maybe formed integral with the operating handle I51 terclockwise.

pivoted at I58. Therod I5I is made of two parts to provide adjustment of the length between the pivot I55 and the shoulder I52.

A pair of arms I59, IE is fixed to opposite ends of a vertical shaft parallel to the frame plate 2, the arm I59 having a bifurcated end portion extending about shaft 80 between plate 2 and arm I4I whereby to reciprocate the arm against the action of spring I43, and the arm I60 being provided with a cam rollerpivoted on a vertical axis. A cam plate IBI is formed integral with the handle I51 and the plate I56, and is so formed that initial counterclockwise movement of the handle from the position shown in Fig. 5initially results in turning the arms I59, l60clockwise, as seen in plan, which will in turn move arm I4I away from plate 2 and out of line with trigger I45. Upon further movement of handle I51, the cam plate IGI holds the arm MI in moved position and brings shoulder I52 into engagement with lever I48, then turning the lever I48 coun- The spring I62 turns the trigger I45 into position to hold lever I48 in its move position. I

Pulling the handle as above described will obviously, throughthe clutchshaft 33, set the machine in operation. As the clamp moves from neutral vertical position to the right indexing position of Fig. 3, the shaft 89 and arm I turn counterclockwise, as shown in Fig. 5. The arm I4I will then overlap trigger M5. The handle is then released andis moved to the normal position shown, by spring I63. When the machine reverses to left indexing, as described heretofore,

,the arm MI is turned clockwise and becomes by cam 85, the arm MI is turned into edgeengagement Withthe trigger I45 and presses it sufficiently far that the trigger disengages from the lever I 48, which, under action of spring I50, stops the machine automatically.

A rod IE4 is pivoted at I65 to the handle I51 and is provided with a shoulder I66 and means to adjust the distance from the pivot to the shoulder. The reduced endportion I61 ofrod I64 is arranged to slide in a sleeve pivotedin trigger I45. The. rod is so adjusted that, if the handle is moved clockwise from the normal position shown in Fig. 5, trigger I45 will release lever I48, stopping the machine. It should be noted that stoppage of the machine, either manually or automatically, stops the train which rotates the head and indexing thereof but that such stoppage does not stop rotation of the grinding wheel. An adjustable stop I68 is provided to limit counterclockwise movement of the trigger.

A gear ItiB is fixed to shaft I51 rctatably carried in the carriage frame plate I0 with the lower end of the shaft in driving engagement with pump I58. The gear I56 engagesthe constantly driven gear 3i whereby the pump is driven at all times that the grinding wheel is rotating. The inlet I89 of the pump depends therefrom and dips into a tank I supported on the base.

The outlet of the pump communicates through a gland III supported by abracket I12 with a pipe H3 which passes through the hollow shaft 2i and is secured inguide plate 54. At the end of pipe I13, a duct is provided in plate 54 comis of necessity fixed, since the sleeve 84 is turned a fixed number of degrees per rotation of gear 14. Accordingly, shaft 85 is made easily removable whereby a substitute shaft and sleeve, having a 84 may be inserted in the carriage frame and amatching shaft inserted.

As has been noted, the distance of the grinding wheel from the grinding head axis may be adjusted by turning the thumb nut 03 and fixing it in adjusted. position by the set screws 59. This adjustment gives control over the radius of curvature of the individual scallops. With any given shaft 85, movement of the grinding wheel toward the center of revolution thereof willproduce a blade having deeper scallops in proportion to their length; i. e., a blade having longer, more pointed teeth.

These two adjustments, the pitch of the thread of shaft 85 and the radius of revolution of the grinding wheel give complete control over the characteristics of the blade.

With blades having various center-to-center size of scallop, the ground length of blade of necessity varies somewhat. Also, it may be desirable to produce blades of various length of identical tooth character. Accordingly, the cam roller 88 andthe arm I38 are adjustable longie tudinally of the machine. For this purpose, a lead screw I8i3 is rotatably carried in the lower portion of the machine and is provided at one end with a crank I8I and a lock nut I82. The screw I80 threadedly engages a support I83 provided with guide bushings engaging the shafts 89 and I02. This support carries the arm 81 and its cam roller, the operating arm I38, and also a gauging sleeve I84 which slides with support I83 on shaft I02. This shaft I02 is provided with a plurality of gauging scales corresponding with the indexing using the various threaded shafts 85. With any particular shaft 85 in the machine, the end of sleeve I84 may be set at any of the scale markings on the: corresponding scale, as shown in Fig. 1, and the machine will reverse after cutting the indicated number of scallops. To bring: any of the various scales on shaft I02 in view, the shaft is made rotatable under action of thumb nut I15.

For a better understanding of. the machine, considerable description of the operation of Various assemblies has above been given in connec tion with the description of each assembly. In order to avoid repetition andas the detail operation should now be understood, the following statements of operation are intended to coordinate the various statements of operation.

With the shaft 05 and the radius of revolution of thegrlnding wheel adjusted to produce a blade of thedesired characteristics, the hand wheel I8I is adjusted until the sleeve indicates the desired length of blade on the proper scale. The carriage is positioned, as shown in Fig. l, and the arm I4I is adjusted so as to trip the trigger I45 when the clamp assembly is moved to neutral position under action of the lefthand cam roller.

The belts 20 and 24 are properly tensionedby adjustment of motor bracket II and belttighten- "er 21. The -motor may then be started, thereby g claims appended hereto.

rotating the. grinding wheel, conmiuniczating power to .the clutch, and driving the pump. A work-piece may then be inserted in the clamp.

The handle may then be pulled forward, whereby the clutch is engaged, the work moved to grinding position, and grinding initiated. When the grinding has proceeded to the right end of the blade, as predetermined by the hand wheel lill, the machine automatically reverses, turning the blade over and moving it to the opposite side of the center of revolution. Due to the relation of grinding and indexing of right hand and left hand operation, above described, the first cut after reversal is madeprior to indexing thereafter. While in describing the timing above, grinding through a 120 are was indicated, this varies with therelation of the center-to-center distance of the scallops and the radius of revolution of the grinding wheel. Grinding on the second side then continues automatically until the blade is completed when the clutch is disengaged under action of the cam roller I05. The finished blade may then be removed from the machine. For producing more blades of the same variety, all that is necessary is toinsert the workpiece, pull the handle and, when operation is complete, remove the blade.

Blades produced in accordance with this invention are far superior to the blades at present on the market. Thus, a common drawback of present blades is that the grinding is effected in a direction transverse to the length of the blade. This results in the friction between the blades and the bread being unduly great. Blades produced on the machine of this invention have the grain of the grind at all places parallel to the ground edge, thereby considerably reducing the friction and resulting in the drag of the blades on the bread being considerably less.

The blades produced in accordance with this invention are further characterized by their long, thin cutting points. Thus, these blades have a greater ground depth at the points than at the centers of the scallops, and a section of a blade transverse to the length of the blade through a cutting point shows that the points are hollow ground. On the other hand, a blade made by wrapping a blank into a cylinder and grinding facettes is characterized by relatively blunt points. These comparisons are on the basis of blades of the same size scallops and with the angles between ground surfaces at the middle of a scallop the same.

Theabove description is illustrative of the invention and is not to be taken as indicative of the scope thereof, the scope being defined by the While I have above described a machine in which the carriage is .movable and a fixed length blade is ground on its opposite sides in a longitudinally fixed position, it is obvious that within the broad scope of this invention considerable latitude is encompassed within the scope thereof. Thus, for

.instance, the grinding head may be rotated on a fixed axis and the blade be indexed inresponse to rotation thereof and be automatically reversjable and be provided with an automatic stop similar to that disclosed above.

driven synchronously-and the material indexed step-by-step in response to movement of grinding, heads when out of contact with the material.

In, connectionwiththe. grinder head itglS to be noted-that while, the shaft of the abrasive wheel has been shown at an acute angle to the axis of revolution and the wheel shown as cylindrical the shaft maybe at any angle, for instance, a right angle, and a truncated conical wheel emp yed.

Having, now described my invention, I claim:

, 1., A machine for grinding scalloped bevel edges,'comprising an abrading wheel, means for rotating said wheel, means for revolving said wheel about an axis substantially intersecting the axis of rotation of said wheel, means for positioning a work-piece with the portion to be ground, substantially perpendicularly to the axis of revolution of said wheel and at a position along saidaxis and spaced therefrom a distance such that the periphery of said wheel forms an arcuate bevel in the edge of said work-piece,

and means for relatively indexing the wheel and said work-piece, said work-piece in the region of grinding having the longitudinal extent thereof directed substantially tangentially of the orbit of said wheel, whereby to grind a series of arcuate bevels.

- 2.v A machine for grinding scalloped bevel edges, comprising an abrading wheel, means for rotating said wheel, means for revolving said wheel about an axis substantially intersecting the axis of rotation of said wheel, means for positioning-a work-piece: with the portion to be ground substantially perpendicularly to the axis of revolution'of said wheel and at a position along said axis and spaced therefrom a distance such that the periphery of said wheel forms an arcuate bevel in the edge of said work-piece,,

said work-piece in the region of grinding having the longitudinal extent thereof directed substantially tangentially of the orbit of said wheel, and means actuated by said means for revolving said wheel when said wheel is in a position of its cycle in which it is out of contact with said work-piece for relatively indexing the wheel and said work-piece whereby to grind a series of .arcuate bevels.

3. A machine for grinding curved bevels, comprising an abrading wheel, means for rotating said wheel, means for revolving said wheel about an axis substantially intersecting the axis of rotation of said wheel, means for relatively posi-- :tioning a work-piece and said wheel so that the portion of the work-piece to be ground is substantially perpendicular to the axis of revolution and'that said wheel is in contact with said Workpiec,e,-'said work-piece in the region of grinding having the longitudinal extent thereof directed substantially tangentially of the orbit of said wheel, with the grinding face of said wheel at an angle to said axis of revolution at the point of contact with said work, whereby an arcuate bevel is produced in said work-piece, and means actuated by the second named means for relatively indexing the work-piece and grinding wheel to a similar working position spaced along the work-piece.

4. A machine for grinding scalloped bevel edges, comprising an abrading wheel, means for rotating said wheel, means for revolving said wheel about an axis substantially intersecting the axis of rotation of said wheel, means for relatively positioning, a work-piece and said wheel so that the portion of the work-piece to be ground is substantially perpendicular to the axis of revolution of said wheel, with the grind ing faceof said Wheel at, an acute angle to the axis of revolution. at; a. point of contact with said work, said work-piece. infthe region of grinding having the longitudinal extent thereof directed substantially tangentially of the, orbit of said wheel, and meansfor relatively indexing said work and said wheela distance less than the. diameter of revolution of the grinding face atsaid point wherebyito grind a series of intersectingscallop-ed bevels. l v

5. A machine for grinding. bevel edges, an abrading wheel, means: for rotating said wheel,

means for revolving said wheel about an axis sides up in said positions and equally spaced from. the axis of revolution in both said positions.

6. A machine for, grinding bevel edges, an abrading wheel, means for rotating said wheel, means for revolving said wheel, means tosecure a work-piece in a position substantially perpendicularly to the axis of. revolution of said wheel and to one side thereof and ata position therealong in whichit is ,contacted by said wheel in therevolution thereof, means to move said Workpiece to a corresponding position on the opposite side of the axis of revolution with the workpiece the other side up, means to relatively, in-

dex the wheel and work-piece in the first men.- tioned position of thework-piece, and means to relatively index the wheel and work-piece in the second mentioned position of the work-piece to the same positions of the wheel along said workpiece as when in the first mentioned position.

'7. In a machine of the character described, a tool, means rotatably mounted carrying said tool spaced from the axis of rotation,means to support a sheet material, work-piece in a position operative with respect tosaid tool duringa portion of therotation of said means, and substan tially perpendicular to the axis of rotation and at one side thereof, and means to move said work-piece to. the cornplermental position on the opposite side of the axis, with the ,work-piece the, other side up. I

8. In a machine ofthe character described, a.

tool, means rotatably mounted carrying said tool spaced from the axisof rotatiommeans to supposite side of the axis, with the Work-piece the other side up, indexing means timed with respect to the rotation of said means for indexing the.

carrying means relativelyalong the work-piece in accord with the cycle, related to rotation of said carrying means, as follows; operation by the tool,

blank, index blank, repeating this, cycle until the reversing cycle, as follows; operation by the tool,

movement of the work-piece to the complemental position, operation by the tool,,blank,, index in the opposite direction,blank, then repeating, the last four cycle periods.

9. In amachine of thecharacter described, a

frame, a carriage mounted for reciprocatiomon said frame, a tool head rotatably mounted rm said. v

carriage, meansnormally constantly to rotate said head, cooperatingmeans on said frame and carriage to effect reciprocation of the carriage, drive means on said carriage to effect limited actuation of said cooperating means, and cooperating means on said head and carriage for initiating operation of said drive means whereby reciprocation of said carriage ,is eifected only in predetermined angular position of said head.

10. In amachine of the character described, a frame, a carriagemounted for reciprocation on said frame, a tool head rotatably mounted on said carriage, means normally constantly to rotate said head, cooperating meanson said frame and carriage to effect-reciprocation of the carriage, drive means on said carriage to effect limited actuation of said cooperating means on said head and means whereby reciprocation in one direction of said carriage is effected only in predetermined angularposition of said head, one of said cooperating means on said head and carriage being movable out of position to engage the other and into a position to engage an alternative cooperating means, said one of said cooperating means and said alternativemeans cooperating to effect reciprocation only in another predetermined angular position of said head.

11. In a machine of the character described, a tool-support arranged to rotate on an axis therethrough, a tool supported thereby in a position spaced from said axis for movement in. a plane perpendicular to said axis of rotation, and

a work-support for sheet material type of work arranged to position said Work in tool-engaging position in a plane perpendicular to andat one side of said work, said work-support being mounted for. rotation through an angle of about on an axis intersecting the axis of rotation of said tool-support.

"work-support for sheet material type of work ar-.

ranged to position said work in tool-engaging position in a plane perpendicular to and to one side of said work, said work-support being mounted for rotation through an angle of about 180 on an axis intersecting the axis ofrotation of said tool-support, and means for moving the toolsupport step-by-step in a direction parallel to the axis of rotation: of the work-support.

13. In a machine of the character described, a tool-support arranged to rotate on an axis therethrough, a tool supported thereby in a position spaced from said axis for movement in a plane perpendicular to saidaxis of rotation, a worksupport for sheet material'type of work arranged to position said work in tool-engaging position in a plane perpendicular to and to one side ofsaid tool, said work-support being mounted for rotationthrough an angle of about 180 on an axis intersecting the axis of rotation of said toolsupport, means for moving said tool-support alongthe; axis of rotation of said work-support,

and means under control of said tool-support for 'eifectingsaid rotation of the work-support after a predetermined extent of movement along the axis, said last named means also shifting the means for moving toeflect reversalof the direction of said relative movement.

14. In a machine of the class described, a

frame, a work-support carried by said frameland 7 carriage for initiating operation of said drive frame on the side of the plane defined by the terminal positions of the work-support away from the direction in which the work-support oscillates, said work-support and tool-support being along the path ofjmovement of said carriage in 20.-

arranged relatively to reciprocate parallel to said axis'along said work-support, and a pair ofmembers mounted on the carriage to move therewith and support the work-supportin either of its terminal positions. v

15. In a machine of the character described, a work support arranged to oscillate through an arc of about 180 from one terminal position to another, a'carriage, means on said carriage to effect indexing thereof along said support and toward one end of said support, reversing means the direction of said end for engagement therewith'for eifecting' reversal of the direction of indexing by said indexing means, an arm pivoted to said carriage in a position to support said worksupport in one of said terminal positions, and releasing means along the path of movement of said carriage in said direction positioned operative to'release-said-arm prior to operation of said reversing means, 1

16. In a'machineof thecharacter described, a frame, a carriage mounted for reciprocation in either direction on said frame, a tool-support mounted for rotation on said carriage, dual means for initiating each step of step-by-step reciprocation of the carriage mounted in spaced positions axially with respect to said tool-support for rotation concurrently therewithflneans mounted on said carriage 'shiftable from a position to be actuated by one of said dual means to a position tobe actuated by the other of said dual means for effectingreciprocation in one direction when actuated by one of said dual means and in the other direction when actuated by the other of said dual means.

7 17. In a machine of the character described, a

grinding head body member mounted for rotation about an axis'therethrough, a drive plate mounted in said body member for rotation with relation to said body member about said axis, a shaft carried by said member at an angle to said axis and a drivewheel in frictional engagement with said drive plate and in driving relation with said shaft, means for differentially rotating said member and said plate, and a grinding wheel mounted on said shaft.

18. The method of forming bevel scallop edges on sheet material work-pieces, comprising rotating a grinding wheel on its axis, continuously revolving said wheel. about an axis external to said wheel, while rotating, said axis of revolution being so located that the wheel moves into and out of engagement with a sheet material work-piece which is positioned so that one edge thereof is substantially tangential to the orbit of said wheel, whereby scallops are cut in said edge,.the revolving of said wheelcyclically, first, moving said grinding wheel into grinding engagementv with the Work-piece, second, moving said wheel while in engagement in a circular path, third, moving said wheel out of engagement with the work-piece, and fourth, moving the wheel while out of engagement tothe initial position of the first stage of the cycle, and relatively moving the axis of revolution and the \Work-piece in a direction parallel tothe plane of the'work-piece during the fourth stage of the 1 cycle.

is substantially tangential to the orbit of said wheel, whereby scallops are cut in said edge, the

revolving of said wheel cyclically, first, moving said grindingwheel into grinding engagement with the Work-piece, second, moving said wheel while in engagement in a circular path, third, moving said Wheel out of engagement, and fourth, moving the wheel while out of engagement to the position of the first stage of the cycle, and relatively moving the axis'of I'BVOlUr,

tion and the work-piece in a direction parallel to the plane of the work-piece during the fourth stage of the cycle.

20. A machine fon grinding scalloped bevel edges comprising an abrading wheel, means for rotating said wheel, means for revolving said wheel about an axis substantially intersecting the axis of rotation of said wheel, and means for relatively positioning a work-piece, having a substantially flat surface and an edge to be scallop ground, in a position with said surface substantially perpendicular to the axis of revolution of the wheel, with the edge to be ground substantially tangential to the orbit of the wheel, with the work-piece spaced along the axis of revolution so that the wheel engages the work-piece, and with the body of the Work-piece, except for the portion being ground, lying outside of the orbit of the wheel.

21. A machine for grinding scalloped bevel edges comprising an abrading wheel, means for rotating said wheel, means for revolving said wheel about an'axis substantially intersecting the axis of rotation of said wheel, means for rela tively positioning a work-piece, having a substantially flat surface and an edge to be scallop ground, in a position with said surface substantially perpendicular to the axis of revolution of the wheel, with the edge to be ground substantially tangential to the orbit of the wheel, with the work-piece spaced along the axis of revolution so that the wheel engages the workpiece, and with the body of the Work-piece, except for the. portion being ground, lying outside of the orbit of the Wheel, and means to relatively index the work-piece and the axis of revolution of said wheel to a position similar to the defined position, but in which the axis of revolution is relatively, spaced along the edge of the workpiece a distance such that the scallops ground in the edge of the blade in the two positions form intersecting surfaces on the surface of the workpiece.

22,A machine for grinding scalloped bevel edges comprising an abrading wheel, means for rotating said wheel, means for revolving said tially tangential to the orbit ofthe wheel, with the work-piece spaced along the axis of revolution so that the wheel engages the work-piece, and with the body of the work-piece; except for the portion being ground, lying outside of the orbit of the wheel, and automatic means, operative responsive to revolution of said abrading wheel through that portion of its orbit in which it is out of contact with said work-piece, to rela- 

